okay, this works (not sure if it is much more elegant, but...)

perl script:

#!/usr/bin/perl

my($JAVA_CLASSPATH) = @ARGV;

$LAUNCH_JAVA = $JAVA_CLASSPATH."/launch_java.sh";

open(FH, "$LAUNCH_JAVA $JAVA_CLASSPATH |")
    or die "Couldn't launch 'launch_java.sh': $! / $?";
    
my $kid = <FH>;
$kid =~ s@\n@@;
    
END {
    if ($kid) {
        kill 9 => $kid; # bang
    };
};

print "pid: $kid\n\npress return to exit script...\n\n";

<STDIN>;
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shell script (launch_java.sh):

#/bin/bash

java -classpath $1 TextEntry 2> /dev/null &
echo $!
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